Filter cartridge; components thereof; and methods

ABSTRACT

An air filter cartridge includes a coiled media pack with inlet flutes and outlet flutes. The coiled media pack has first and second rounded ends with at least a first straight side and a second side. The coiled media pack has: (i) a length extending along a straight line from a center of the first rounded end to a center of the second rounded end; (ii) a first width between the first straight side and second side; the first width being perpendicular to the length; and (iii) a second width thereacross; the second width being perpendicular to the length. The first width is narrower than the second width.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 15/684,001,filed Aug. 23, 2017 which is a continuation of application Ser. No.13/947,833, filed Jul. 22, 2013, issued as U.S. Pat. No. 9,751,036 onSep. 5, 2017, which is a continuation of application Ser. No.12/712,845, filed Feb. 25, 2010, issued as U.S. Pat. No. 8,491,684 onJul. 23, 2013, which claims priority under 35 U.S.C. § 119(e) to U.S.provisional patent application Ser. No. 61/156,278, filed Feb. 27 2009,which applications are incorporated herein by reference in theirentirety.

FIELD OF THE DISCLOSURE

The present disclosure concerns filters for cleaning air, for example,for use in dust collectors and other equipment. In particular, thisdisclosure concerns z-filters for use in dust collectors and methods forcleaning them.

BACKGROUND

Dust collectors are used to clean particulate matter from airflowstreams. One embodiment of dust collectors includes bag house filters.Bag house filters include: a housing, a dirty air inlet, a clean airoutlet, and a tube sheet having a plurality of apertures. The tube sheetseparates the housing between a dirty air side and a clean air side andholds filter bags. The bags are made of a filter media so that as dirtyair flows from the dirty air side to the clean air side, the air mustflow through the bags and the filter media of the bags preventsparticulate matter from reaching the clean air side.

Improvements are desirable.

SUMMARY OF THE DISCLOSURE

Z-filters are described in reverse flow, reverse air, and reverse pulsesystems that are capable of cleaning particulate matter from airflowstreams. It is noted that not all the specific features described hereinneed to be incorporated in an arrangement for the arrangement to havesome selected advantage according to the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary, schematic, perspective view of a single facerstrip of z-filter media comprising a fluted sheet secured into a facingsheet.

FIG. 2 is an enlarged, schematic, fragmentary view of a single facersheet comprising fluted media secured to facing media.

FIG. 3A includes a schematic, fragmentary, cross-sectional view of afurther fluted media configuration in a single facer media pack.

FIG. 3B includes a schematic, fragmentary, cross-sectional view of astill further alternate flute definition in a media pack comprisingsingle facer strips.

FIG. 3C includes a schematic, fragmentary, cross-sectional view of yetanother flute definition in a media pack comprising single facer strips.

FIG. 4 is a schematic view of a process for making single facer mediaaccording to the present disclosure.

FIG. 5 is schematic, cross-sectional view of an example darted flute.

FIG. 6 is schematic, perspective view of a coiled media constructioncomprising a coiled sheet of single facer material.

FIG. 7 is a schematic, perspective view of a stacked media construction.

FIG. 8 is a schematic, perspective view of a first embodiment of a dustcollector utilizing a rotating reverse pulse system and a filtercartridge having z-filter media.

FIG. 9 is a schematic, perspective view of a similar dust collector asFIG. 8 utilizing filter cartridges of z-media and a rotating reversepulse cleaning system.

FIG. 10 is a schematic, perspective view of another embodiment of a dustcollector utilizing filter cartridges of z-media and having a reverseflow cleaning system.

FIG. 11 is another perspective view of a dust collector similar to thedust collector of FIG. 10 utilizing filter cartridges of z-media andhaving a reverse flow cleaning system.

FIG. 12 is a schematic, perspective view of another embodiment of a dustcollector; this dust collector also utilizing filter cartridges ofz-media and having a double rotating reverse flow cleaning system.

FIG. 13 is a perspective view of one embodiment of a filter cartridgeutilizing z-media that can be used in any of the dust collectors ofFIGS. 8-12 .

FIG. 14 is a perspective view of an end cap on the filter cartridge ofFIG. 13 .

FIG. 15 is a side elevational view of the filter cartridge of FIG. 13 .

FIG. 16 is a bottom plan view of the filter cartridge of FIG. 13 .

FIG. 17 is a cross sectional view of a portion of the filter cartridgeof FIG. 13 , the cross-section being taken along the line A-A of FIG. 15.

FIG. 18 is an enlarged view of a portion of the filter cartridgedepicted in FIG. 16 .

FIG. 19 is a top plan view of an alternate embodiment of a filtercartridge usable in any of the dust collectors depicted in FIGS. 8-12 .

FIG. 20 is a top plan view of another embodiment of a filter cartridgeusable with any of the dust collectors of FIGS. 8-12 .

FIG. 21 is a schematic, perspective view of another embodiment of a dustcollector utilizing z-filter media cartridges and having a reverse pulsecleaning system.

FIG. 22 is a perspective view of one embodiment of an arm having nozzlesusable with the dust collectors of FIGS. 8-12 and 21 .

FIG. 23 is another perspective view of the arm of FIG. 22 .

FIG. 24 is a side elevational view of the arm of FIG. 23 .

FIG. 25 is a cross sectional view of the arm of FIG. 24 , thecross-section being taken along the line A-A of FIG. 24 .

FIG. 26 is an end view of the arm of FIG. 24 .

FIG. 27 is an enlarged view of the cross-section of the nozzle andsleeve depicted in FIG. 25 .

FIG. 28 is a schematic diagram illustrating principles of operation ofan air knife on a media pack of z-filter medial FIG. 29 is a schematic,perspective view of a portion of a dust collector usable with acartridge of z-filter media and having translational movement of areverse flow or a reverse pulse cleaning system.

FIG. 30 is a perspective view of a portion of the dust collector of FIG.29 .

FIG. 31 is a perspective, schematic view of a portion of the dustcollector of FIG. 29 .

FIG. 32 is a perspective view of an air knife usable in the system ofFIGS. 29 and 30 .

DETAILED DESCRIPTION I. Z-Filter Media Configurations, Generally

Fluted filter media can be used to provide fluid filter constructions ina variety of manners. One well known manner is as a z-filterconstruction. The term “z-filter construction” as used herein, is meantto refer to a filter construction in which individual ones ofcorrugated, folded or otherwise formed filter flutes are used to definesets of longitudinal filter flutes for fluid flow through the media; thefluid flowing along the length of the flutes between opposite inlet andoutlet flow ends (or flow faces) of the media. Some examples of z-filtermedia are provided in U.S. Pat. Nos. 5,820,646; 5,772,883; 5,902,364;5,792,247; 5,895,574; 6,210,469; 6,190,432; 6,350,296; 6,179,890;6,235,195; Des. 399,944; Des. 428,128; Des. 396,098; Des. 398,046; and,Des. 437,401; each of these fifteen cited references being incorporatedherein by reference.

One type of z-filter media utilizes two specific media components joinedtogether, to form the media construction. The two components are: (1) afluted (typically corrugated) media sheet; and, (2) a facing mediasheet. The facing media sheet is typically non-corrugated, however itcan be corrugated, for example perpendicularly to the flute direction asdescribed in commonly assigned published PCT application WO 05/077487,incorporated herein by reference.

The fluted (typically corrugated) media sheet and the facing mediasheet, together, are used to define media having parallel inlet andoutlet flutes; i.e. opposite sides of the fluted sheet operable as inletand outlet flow regions. In some instances, the fluted sheet andnon-fluted sheet are secured together and are then coiled to form az-filter media construction. Such arrangements are described, forexample, in U.S. Pat. Nos. 6,235,195 and 6,179,890, each of which isincorporated herein by reference. In certain other arrangements, somenon-coiled sections of fluted media secured to flat media, are stackedon one another, to create a filter construction. An example of this isshown herein at FIG. 7 and described in FIG. 11 of 5,820,646,incorporated herein by reference.

Typically, coiling of the fluted sheet/facing sheet combination arounditself, to create a coiled media pack, is conducted with the facingsheet directed outwardly. Some techniques for coiling are described inU.S. provisional application 60/467,521, filed May 2, 2003 and PCTApplication US 04/07927, filed Mar. 17, 2004, published Sep. 30, 2004 asWO 2004/082795, incorporated herein by reference. The resulting coiledarrangement generally has, as the outer surface of the media pack, aportion of the facing sheet, as a result. In some instances a protectivecovering can be provided around the media pack.

The term “corrugated” when used herein to refer to structure in media,is meant to refer to a flute structure resulting from passing the mediabetween two corrugation rollers, i.e., into a nip or bite between tworollers, each of which has surface features appropriate to cause acorrugation affect in the resulting media. However, the term“corrugated” is meant to apply even if the media is further modified ordeformed after corrugation, for example by the folding techniquesdescribed in PCT WO 04/007054, published Jan. 22, 2004, incorporatedherein by reference.

Corrugated media is a specific form of fluted media. Fluted media ismedia which has individual flutes (for example formed by corrugating orfolding) extending thereacross.

Serviceable filter element or filter cartridge configurations utilizingz-filter media are sometimes referred to as “straight through flowconfigurations” or by variants thereof. In general, in this context whatis meant is that the serviceable filter elements generally have an inletflow end (or face) and an opposite exit flow end (or face), with flowentering and exiting the filter cartridge in generally the same straightthrough direction. (The term “straight through flow configuration”disregards, for this definition, any air flow that passes out of themedia pack through the outermost wrap of facing media.) The term“serviceable” in this context is meant to refer to a media containingfilter cartridge that is periodically removed and replaced from acorresponding air cleaner. In some instances, each of the inlet flow endand outlet flow end will be generally flat or planar, with the twoparallel to one another. However, variations from this, for examplenon-planar faces are possible.

In general, the media pack includes appropriate seal material therein,to ensure there is no unfiltered flow of air through the media pack, inextension from front flow face (an inlet flow face) completely throughand outwardly from opposite oval face (outlet flow face).

A straight through flow configuration (especially for a coiled mediapack) is, for example, in contrast to serviceable filter cartridges suchas cylindrical pleated filter cartridges of the type shown in U.S. Pat.No. 6,039,778, incorporated herein by reference, in which the flowgenerally makes a turn as its passes through the serviceable cartridge.That is, in a U.S. Pat. No. 6,039,778 filter, the flow enters thecylindrical filter cartridge through a cylindrical side, and then turnsto exit through an end face (in forward-flow systems). In a typicalreverse-flow system, the flow enters the serviceable cylindricalcartridge through an end face and then turns to exit through a side ofthe cylindrical filter cartridge. An example of such a reverse-flowsystem is shown in U.S. Pat. No. 5,613,992, incorporated by referenceherein.

The term “z-filter media construction” and variants thereof as usedherein, without more, is meant to refer to any or all of: a web ofcorrugated or otherwise fluted media secured to (facing) media withappropriate sealing to inhibit air flow from one flow face to anotherwithout filtering passage through the filter media; and/or, such a mediacoiled or otherwise constructed or formed into a three dimensionalnetwork of flutes; and/or, a filter construction including such media.In many arrangements, the z-filter media construction is configured forthe formation of a network of inlet and outlet flutes, inlet flutesbeing open at a region adjacent an inlet face and being closed at aregion adjacent an outlet face; and, outlet flutes being closed adjacentan inlet face and being open adjacent an outlet face. However,alternative z-filter media arrangements are possible, see for example US2006/0091084 A1, published May 4, 2006, incorporated herein byreference; also comprising flutes extending between opposite flow faces,with a seal arrangement to prevent flow of unfiltered air through themedia pack.

In FIG. 1 herein, an example of media 1 useable in z-filter media isshown. The media 1 is formed from a fluted (corrugated) sheet 3 and afacing sheet 4. Herein, a strip of media comprising fluted sheet securedto facing sheet will sometimes be referred to as a single facer strip,or by similar terms.

In general, the corrugated sheet 3, FIG. 1 is of a type generallycharacterized herein as having a regular, curved, wave pattern of flutesor corrugations 7. The term “wave pattern” in this context, is meant torefer to a flute or corrugated pattern of alternating troughs 7 b andpeaks 7 a. The term “regular” in this context is meant to refer to thefact that the pairs of troughs and peaks (7 b, 7 a) alternate withgenerally the same repeating corrugation (or flute) shape and size.(Also, typically in a regular configuration each trough 7 b issubstantially an inverse of each peak 7 a.) The term “regular” is thusmeant to indicate that the corrugation (or flute) pattern comprisestroughs and peaks with each pair (comprising an adjacent trough andpeak) repeating, without substantial modification in size and shape ofthe corrugations along at least 70% of the length of the flutes. Theterm “substantial” in this context, refers to a modification resultingfrom a change in the process or form used to create the corrugated orfluted sheet, as opposed to minor variations from the fact that themedia sheet 3 is flexible. With respect to the characterization of arepeating pattern, it is not meant that in any given filterconstruction; an equal number of peaks and troughs are necessarilypresent. The media 1 could be terminated, for example, between a paircomprising a peak and a trough, or partially along a pair comprising apeak and a trough. (For example, in FIG. 1 the media 1 depicted infragmentary has eight complete peaks 7 a and seven complete troughs 7b.) Also, the opposite flute ends (ends of the troughs and peaks) mayvary from one another. Such variations in ends are disregarded in thesedefinitions, unless specifically stated. That is, variations in the endsof flutes are intended to be covered by the above definitions.

In the context of the characterization of a “curved” wave pattern ofcorrugations, the term “curved” is meant to refer to a corrugationpattern that is not the result of a folded or creased shape provided tothe media, but rather the apex 7 a of each peak and the bottom 7 b ofeach trough is formed along a radiused curve. Although alternatives arepossible, a typical radius for such z-filter media would be at least0.25 mm and typically would be not more than 3 mm. (Media that is notcurved, by the above definition, can also be useable.)

An additional characteristic of the particular regular, curved, wavepattern depicted in FIG. 1 , for the corrugated sheet 3, is that atapproximately a midpoint 30 between each trough and each adjacent ridge,along most of the length of the flutes 7, is located a transition regionwhere the curvature inverts. For example, viewing back side or face 3 a,FIG. 1 , trough 7 b is a concave region, and peak 7 a is a convexregion. Of course when viewed toward front side or face 3 b, trough 7 bof side 3 a forms a peak; and, peak 7 a of face 3 a, forms a trough. (Insome instances, region 30 can be a straight segment, instead of a point,with curvature inverting at ends of the segment 30.)

A characteristic of the particular regular, curved, wave patterncorrugated sheet 3 shown in FIG. 1 , is that the individual corrugationsare generally straight. By “straight” in this context, it is meant thatthrough at least 70% (typically at least 80%) of the length betweenedges 8 and 9, the peaks 7 a and troughs 7 b do not change substantiallyin cross-section. The term “straight” in reference to corrugationpattern shown in FIG. 1 , in part distinguishes the pattern from thetapered flutes of corrugated media described in FIG. 1 of WO 97/40918and PCT Publication WO 03/47722, published Jun. 12, 2003, incorporatedherein by reference. The tapered flutes of FIG. 1 of WO 97/40918, forexample, would be a curved wave pattern, but not a “regular” pattern, ora pattern of straight flutes, as the terms are used herein. Referring tothe present FIG. 1 and as referenced above, the media 1 has first andsecond opposite edges 8 and 9. When the media 1 is coiled and formedinto a media pack, in general edge 9 will form an inlet end for themedia pack and edge 8 an outlet end, although an opposite orientation ispossible.

In the example shown, adjacent edge 8 is provided sealant, in thisinstance in the form of a sealant bead 10, sealing the corrugated(fluted) sheet 3 and the facing sheet 4 together. Bead 10 will sometimesbe referred to as a “single facer” bead, since it is a bead between thecorrugated sheet 3 and facing sheet 4, which forms the single facer ormedia strip 1. Sealant bead 10 seals closed individual flutes 11adjacent edge 8, to passage of air therefrom.

In the example shown, adjacent edge 9, is provided sealant, in thisinstance in the form of a seal bead 14. Seal bead 14 generally closesflutes 15 to passage of unfiltered fluid therein, adjacent edge 9. Bead14 would typically be applied as the media 1 is coiled about itself,with the corrugated sheet 3 directed to the inside. Thus, bead 14 willform a seal between a back side 17 of facing sheet 4, and side 18 of thecorrugated sheet 3. The bead 14 will sometimes be referred to as a“winding bead” since it is typically applied, as the strip 1 is coiledinto a coiled media pack. If the media 1 is cut in strips and stacked,instead of coiled, bead 14 would be a “stacking bead.”

Referring to FIG. 1 , once the media 1 is incorporated into a mediapack, for example by coiling or stacking, it can be operated as follows.First, air in the direction of arrows 12, would enter open flutes 11adjacent edge 9. Due to the closure at edge 8, by bead 10, the air wouldpass through the media shown by arrows 13. It could then exit the mediapack, by passage through open ends 15 a of the flutes 15, adjacent edge8 of the media pack. Of course operation could be conducted with airflow in the opposite direction.

In more general terms, z-filter media comprises fluted filter mediasecured to facing filter media, and configured in a media pack of flutesextending between first and second opposite flow faces. A sealantarrangement is provided within the media pack, to ensure that airentering flutes at a first upstream edge cannot exit the media pack froma downstream edge, without filtering passage through the media.

For the particular arrangement shown herein in FIG. 1 , the parallelcorrugations 7 a, 7 b are generally straight completely across themedia, from edge 8 to edge 9. Straight flutes or corrugations can bedeformed or folded at selected locations, especially at ends.Modifications at flute ends for closure are generally disregarded in theabove definitions of “regular,” “curved” and “wave pattern.”

Z-filter constructions which do not utilize straight, regular curvedwave pattern corrugation (flute) shapes are known. For example in Yamadaet al. U.S. Pat. No. 5,562,825 corrugation patterns which utilizesomewhat semicircular (in cross section) inlet flutes adjacent narrowV-shaped (with curved sides) exit flutes are shown (see FIGS. 1 and 3,of U.S. Pat. No. 5,562,825). In Matsumoto, et al. U.S. Pat. No.5,049,326 circular (in cross-section) or tubular flutes defined by onesheet having half tubes attached to another sheet having half tubes,with flat regions between the resulting parallel, straight, flutes areshown, see FIG. 2 of Matsumoto '326. In Ishii, et al. U.S. Pat. No.4,925,561 (FIG. 1 ) flutes folded to have a rectangular cross sectionare shown, in which the flutes taper along their lengths. In WO 97/40918(FIG. 1 ), flutes or parallel corrugations which have a curved, wavepatterns (from adjacent curved convex and concave troughs) but whichtaper along their lengths (and thus are not straight) are shown. Also,in WO 97/40918 flutes which have curved wave patterns, but withdifferent sized ridges and troughs, are shown.

In general, the filter media is a relatively flexible material,typically a non-woven fibrous material (of cellulose fibers, syntheticfibers or both) often including a resin therein, sometimes treated withadditional materials. Thus, it can be conformed or configured into thevarious corrugated patterns, without unacceptable media damage. Also, itcan be readily coiled or otherwise configured for use, again withoutunacceptable media damage. Of course, it must be of a nature such thatit will maintain the required corrugated configuration, during use.

In the corrugation process, an inelastic deformation is caused to themedia. This prevents the media from returning to its original shape.However, once the tension is released the flute or corrugations willtend to spring back, recovering only a portion of the stretch andbending that has occurred. The facing sheet is sometimes tacked to thefluted sheet, to inhibit this spring back in the corrugated sheet. Themedia may also contain a resin.

The media of the corrugated sheet 3 facing sheet 4 or both, can beprovided with a fine fiber material on one or both sides thereof, forexample in accord with U.S. Pat. No. 6,673,136, incorporated herein byreference.

An issue with respect to z-filter constructions relates to closing ofthe individual flute ends. Typically a sealant or adhesive is provided,to accomplish the closure. As is apparent from the discussion above, intypical z-filter media especially those which use straight flutes asopposed to tapered flutes, large sealant surface areas (and volume) atboth the upstream end and the downstream end are needed. High qualityseals at these locations are critical to proper operation of the mediastructure that results. The high sealant volume and area, creates issueswith respect to this.

Still referring to FIG. 1 , at 20 tack beads are shown positionedbetween the corrugated sheet 3 and facing sheet 4, securing the twotogether. The tack beads can be for example, discontinuous lines ofadhesive. The tack beads can also be points in which the media sheetsare welded together.

From the above, it will be apparent that the corrugated sheet 3 istypically not secured continuously to the facing sheet, along thetroughs or ridges where the two adjoin. Thus, air can flow betweenadjacent inlet flutes, and alternately between the adjacent outletflutes, without passage through the media. However air which has enteredin inlet flute cannot exit from an outlet flute, without passing throughat least one sheet of media, with filtering.

Attention is now directed to FIG. 2 , in which a z-filter mediaconstruction 40 utilizing a fluted (in this instance regular, curved,wave pattern corrugated) sheet 43, and a non-corrugated flat, facing,sheet 44, is depicted. The distance D1, between points 50 and 51,defines the extension of flat media 44 in region 52 underneath a givencorrugated flute 53. The length D2 of the arch-shaped media for thecorrugated flute 53, over the same distance D1 is of course larger thanD1, due to the shape of the corrugated flute 53. For a typical regularshaped media used in fluted filter applications, the linear length D2 ofthe media 53 between points 50 and 51 will generally be at least 1.2times D1. Typically, D2 would be within a range of 1.2-2.0, inclusive.One particularly convenient arrangement for air filters has aconfiguration in which D2 is about 1.25-1.35×D1. Such media has, forexample, been used commercially in Donaldson Powercore™ Z-filterarrangements. Herein the ratio D2/D1 will sometimes be characterized asthe flute/flat ratio or media draw for the corrugated media.

In the corrugated cardboard industry, various standard flutes have beendefined. For example the standard E flute, standard X flute, standard Bflute, standard C flute and standard A flute. Of course other, standard,flutes definitions from the corrugated box industry are known.

It is noted that alternative flute definitions such as thosecharacterized in US 2008/068394 filed Jun. 26, 2007 and US 2009/051670filed Jul. 24, 2009, can be used with air cleaner features ascharacterized herein below. The complete disclosures of each of US2008/068394 and US 2009/05167 are incorporated herein by reference.

In FIGS. 3A-3C, cross-sectional views of exemplary portions offiltration media are shown wherein the fluted sheet has one or morenon-peak ridge extending along at least a portion of the flute length.FIG. 3A shows a fluted sheet having one non-peak ridge provided betweenadjacent peaks, and FIGS. 3B and 3C show fluted sheets having twonon-peak ridges between adjacent peaks. The non-peak ridges can extendalong the flute length any amount including, for example, an amount of20% of the flute length to 100% of the flute length. In addition, thefluted sheet can be provided without non-peak ridges between alladjacent peaks, and can be provided with differing numbers of non-peakridges between adjacent peaks (e.g., alternating zero, one, or twonon-peak ridges in any arrangement). The presence of non-peak ridges canhelp provide more media available for filtration in a given volume, andcan help reduce stress on the fluted sheet thereby allowing for asmaller radius at the peaks and therefore reduced media masking. Suchmedia can be used in arrangements according to the present disclosure.

II. Manufacture of Coiled Media Configurations Using Fluted Media,Generally

In FIG. 4 , one example of a manufacturing process for making a mediastrip (single facer) corresponding to strip 1, FIG. 1 is shown. Ingeneral, facing sheet 64 and the fluted (corrugated) sheet 66 havingflutes are brought together to form a media web 69, with an adhesivebead located therebetween at 70. The adhesive bead 70 will form a singlefacer bead 10, FIG. 1 . An optional darting process occurs at station 71to form center darted section 72 located mid-web. The z-filter media orZ-media strip 74 can be cut or slit at 75 along the bead 70 to createtwo pieces 76, 77 of z-filter media 74, each of which has an edge with astrip of sealant (single facer bead) extending between the corrugatingand facing sheet. Of course, if the optional darting process is used,the edge with a strip of sealant (single facer bead) would also have aset of flutes darted at this location.

Techniques for conducting a process as characterized with respect toFIG. 4 are described in PCT WO 04/007054, published Jan. 22, 2004incorporated herein by reference.

Still in reference to FIG. 4 , before the z-filter media 74 is putthrough the darting station 71 and eventually slit at 75, it must beformed. In the schematic shown in FIG. 4 , this is done by passing asheet of media 92 through a pair of corrugation rollers 94, 95. In theschematic shown in FIG. 4 , the sheet of media 92 is unrolled from aroll 96, wound around tension rollers 98, and then passed through a nipor bite 102 between the corrugation rollers 94, 95. The corrugationrollers 94, 95 have teeth 104 that will give the general desired shapeof the corrugations after the flat sheet 92 passes through the nip 102.After passing through the nip 102, the sheet 92 becomes corrugatedacross the machine direction and is referenced at 66 as the corrugatedsheet. The corrugated sheet 66 is then secured to facing sheet 64. (Thecorrugation process may involve heating the media, in some instances.)

Still in reference to FIG. 4 , the process also shows the facing sheet64 being routed to the darting process station 71. The facing sheet 64is depicted as being stored on a roll 106 and then directed to thecorrugated sheet 66 to form the Z-media 74. The corrugated sheet 66 andthe facing sheet 64 would typically be secured together by adhesive orby other means (for example by sonic welding).

Referring to FIG. 4 , an adhesive line 70 is shown used to securecorrugated sheet 66 and facing sheet 64 together, as the sealant bead.Alternatively, the sealant bead for forming the facing bead could beapplied as shown as 70 a. If the sealant is applied at 70 a, it may bedesirable to put a gap in the corrugation roller 95, and possibly inboth corrugation rollers 94, 95, to accommodate the bead 70 a.

Of course the equipment of FIG. 4 can be modified to provide for thetack beads 20, if desired.

The type of corrugation provided to the corrugated media is a matter ofchoice, and will be dictated by the corrugation or corrugation teeth ofthe corrugation rollers 94, 95. One useful corrugation pattern will be aregular curved wave pattern corrugation, of straight flutes, as definedherein above. A typical regular curved wave pattern used, would be onein which the distance D2, as defined above, in a corrugated pattern isat least 1.2 times the distance D1 as defined above. In exampleapplications, typically D2=1.25-1.35×D1, although alternatives arepossible. In some instances the techniques may be applied with curvedwave patterns that are not “regular,” including, for example, ones thatdo not use straight flutes. Also, variations from the curved wavepatterns shown, are possible.

As described, the process shown in FIG. 4 can be used to create thecenter darted section 72. FIG. 5 shows, in cross-section, one of theflutes 68 after darting and slitting.

A fold arrangement 118 can be seen to form a darted flute 120 with fourcreases 121 a, 121 b, 121 c, 121 d. The fold arrangement 118 includes aflat first layer or portion 122 that is secured to the facing sheet 64.A second layer or portion 124 is shown pressed against the first layeror portion 122. The second layer or portion 124 is preferably formedfrom folding opposite outer ends 126, 127 of the first layer or portion122.

Still referring to FIG. 5 , two of the folds or creases 121 a, 121 bwill generally be referred to herein as “upper, inwardly directed” foldsor creases. The term “upper” in this context is meant to indicate thatthe creases lie on an upper portion of the entire fold 118, when thefold 118 is viewed in the orientation of FIG. 5 . The term “inwardlydirected” is meant to refer to the fact that the fold line or creaseline of each crease 121 a, 121 b, is directed toward the other.

In FIG. 5 , creases 121 c, 121 d, will generally be referred to hereinas “lower, outwardly directed” creases. The term “lower” in this contextrefers to the fact that the creases 121 c, 121 d are not located on thetop as are creases 121 a, 121 b, in the orientation of FIG. 5 . The term“outwardly directed” is meant to indicate that the fold lines of thecreases 121 c, 121 d are directed away from one another.

The terms “upper” and “lower” as used in this context are meantspecifically to refer to the fold 118, when viewed from the orientationof FIG. 5 . That is, they are not meant to be otherwise indicative ofdirection when the fold 118 is oriented in an actual product for use.

Based upon these characterizations and review of FIG. 5 , it can be seenthat a regular fold arrangement 118 according to FIG. 5 in thisdisclosure is one which includes at least two “upper, inwardly directed,creases.” These inwardly directed creases are unique and help provide anoverall arrangement in which the folding does not cause a significantencroachment on adjacent flutes.

A third layer or portion 128 can also be seen pressed against the secondlayer or portion 124. The third layer or portion 128 is formed byfolding from opposite inner ends 130, 131 of the third layer 128.

Another way of viewing the fold arrangement 118 is in reference to thegeometry of alternating ridges and troughs of the corrugated sheet 66.The first layer or portion 122 is formed from an inverted ridge. Thesecond layer or portion 124 corresponds to a double peak (afterinverting the ridge) that is folded toward, and in preferredarrangements, folded against the inverted ridge.

Techniques for providing the optional dart described in connection withFIG. 5 , in a preferred manner, are described in PCT WO 04/007054,incorporated herein by reference. Techniques for coiling the media, withapplication of the winding bead, are described in PCT application US04/07927, filed Mar. 17, 2004 and incorporated herein by reference.

Alternate approaches to darting the fluted ends closed are possible.Such approaches can involve, for example, darting which is not centeredin each flute, and rolling or folding over the various flutes. Ingeneral, darting involves folding or otherwise manipulating mediaadjacent to fluted end, to accomplish a compressed, closed, state.

Techniques described herein are particularly well adapted for use inmedia packs that result from a step of coiling a single sheet comprisinga corrugated sheet/facing sheet combination, i.e., a “single facer”strip.

Coiled media pack arrangements can be provided with a variety ofperipheral perimeter definitions. In this context the term “peripheral,perimeter definition” and variants thereof, is meant to refer to theoutside perimeter shape defined, looking at either the inlet end or theoutlet end of the media pack. Typical shapes are circular as describedin PCT WO 04/007054 and PCT application US 04/07927. Other useableshapes are obround, some examples of obround being oval shape. Ingeneral oval shapes have opposite curved ends attached by a pair ofopposite sides. In some oval shapes, the opposite sides are also curved.In other oval shapes, sometimes called racetrack shapes, the oppositesides are generally straight. Racetrack shapes are described for examplein PCT WO 04/007054 and PCT application US 04/07927, each of which isincorporated herein by reference.

Another way of describing the peripheral or perimeter shape is bydefining the perimeter resulting from taking a cross-section through themedia pack in a direction orthogonal to the winding access of the coil.

Opposite flow ends or flow faces of the media pack can be provided witha variety of different definitions. In many arrangements, the ends aregenerally flat and perpendicular to one another. In other arrangements,the end faces include tapered, coiled, stepped portions which can eitherbe defined to project axially outwardly from an axial end of the sidewall of the media pack; or, to project axially inwardly from an end ofthe side wall of the media pack.

The flute seals (for example from the single facer bead, winding bead orstacking bead) can be formed from a variety of materials. In variousones of the cited and incorporated references, hot melt or polyurethaneseals are described as possible for various applications.

Reference numeral 130, FIG. 6 , generally indicates a coiled media pack130. The coiled media pack 130 comprises a single strip 130 a of singlefacer material comprising a fluted sheet secured to facing sheet coiledaround a center. Typically, the coiling is with facing sheeting directedoutwardly. As previously described, in general a single facer bead andwinding bead would be used, to provide flute seals within the media.

The particular coiled media pack 130 depicted comprises an oval mediapack 131. It is noted that the principles described herein, however, canbe applied starting with the media pack having a circular configuration.

In FIG. 7 , schematically there is shown a step of forming a stackedz-filter media pack from strips of z-filter media, each strip being afluted sheet secured to a facing sheet. Referring to FIG. 7 , singlefacer strip 200 is being shown added to a stack 201 (which can be usedto form a media pack) of strips 202 analogous to strip 200. Strip 200can be cut from either of strips 76, 77, FIG. 4 . At 205, FIG. 7 ,application of a stacking bead 206 is shown, between each layercorresponding to a strip 200, 202 at an opposite edge from the singlefacer bead or seal. (Stacking can also be done with each layer beingadded to the bottom of the stack, as opposed to the top.) Referring toFIG. 7 , each strip 200, 202 has front and rear edges 207, 208 andopposite side edges 209 a, 209 b. Inlet and outlet flutes of thecorrugated sheet/facing sheet combination comprising each strip 200, 202generally extend between the front and rear edges 207, 208, and parallelto side edges 209 a, 209 b.

Still referring to FIG. 7 , in the stack 201 for the media pack beingformed, opposite flow faces are indicated at 210, 211. The selection ofwhich one of faces 210, 211 is the inlet end face and which is theoutlet end face, during filtering, is a matter of choice. In someinstances the stacking bead 206 is positioned adjacent the upstream orinlet face 211; in others the opposite is true. The flow faces 210, 211,extend between opposite side faces 220, 221.

The stack 201 shown being formed into a media pack in FIG. 7 , issometimes referred to herein as a “blocked” stacked media pack. The term“blocked” in this context, is an indication that the arrangement isformed to a rectangular block in which all faces are 900 relative to alladjoining wall faces. Alternate configurations are possible, asdiscussed below in connection with certain of the remaining figures. Forexample, in some instances the stack can be created with each strip 200being slightly offset from alignment with an adjacent strip, to create aparallelogram or slanted block shape, with the inlet face and outletface parallel to one another, but not perpendicular to upper and bottomsurfaces.

In some instances, the media pack will be referenced as having aparallelogram shape in any cross-section, meaning that any two oppositeside faces extend generally parallel to one another.

It is noted that a blocked, stacked arrangement corresponding to FIG. 7is described in the prior art of U.S. Pat. No. 5,820,646, incorporatedherein by reference. It is also noted that stacked arrangements aredescribed in U.S. Pat. Nos. 5,772,883; 5,792,247; U.S. Provisional60/457,255 filed Mar. 25, 2003; and U.S. Ser. No. 10/731,564 filed Dec.8, 2003. All four of these latter references are incorporated herein byreference. It is noted that a stacked arrangement shown in U.S. Ser. No.10/731,504, is a slanted stacked arrangement.

III. Dust Collector Systems, FIGS. 8-12

In reference now to FIGS. 8-12 , a first embodiment of a dust collectorconstructed in accordance with principles of this disclosure is shown inFIG. 8 at reference numeral 300. In the embodiment shown in FIG. 8 , thedust collector 300 includes a housing 302. Housing 302 includes a wall304, generally cylindrical in this embodiment, surrounding an interiorvolume 306. Oriented in communication with the interior volume 306 andbelow the housing 302 is a dust collection hopper 308. The hopper 308 isfrusto-conical in shape, in this embodiment. The hopper 308 collectsdust and debris separated from the air.

As can also be seen in FIG. 8 , the dust collector 300 includes supportstructure 310, such as legs or other support beams oriented to supportthe housing 302 and hopper 308. Typically, the housing 302 and hopper308 are supported vertically above the ground such that a drum or someother container can be placed underneath the hopper 308 to empty thehopper 308 of dust and debris.

The housing 302 defines a dirty air inlet, depicted schematically inthis view at 312 (FIG. 9 ). The inlet 312 draws in unfiltered air intothe housing 302, where it is then in the interior volume 306, and inparticular, is in a dirty air volume 314. The dust collector 300 furtherincludes a tube sheet 316. The tube sheet 316 is within the interiorvolume 306 of the housing 302 and separates the interior volume 306 intoa dirty air side 315 and a clean air side 317. The dirty air side 315 ispart of the dirty air volume 314. The clean air side 317 is part of aclean air volume 318.

In this embodiment, the tube sheet 316 has a generally circular outerperimeter, which matches the cross sectional shape of the housing 302.The tube sheet 316 includes at least one aperture 320. In the embodimentshown, the tube sheet 316 includes a plurality of circumferentiallyspaced apertures 320. In the embodiment of FIG. 8 , the apertures 320are shown covered with filter cartridges 322.

To effectively fill the volume of the tube sheet 316 with filtercartridges 322, the apertures 320 are arranged, as mentioned above,circumferentially spaced from each other and generally wedge-shaped. Thewedge-shape can be also described as being trapezoidal-shaped or atruncated sector-shaped. By “truncated sector”, it is meant, generally,the sector of a circle with the pointed end cut off to form a flat side.By arranging the apertures 320 in this manner, filter media can beoriented within the housing 302 in an efficient and cost effectivemanner, while not having as much area occupied by tube sheet structure316 as other prior art systems.

As can be seen in FIG. 8 , the at least one filter cartridge 322 ismounted in the at least one aperture 320 in order to cover the aperture320. In the system shown, the filter cartridge 322 is removably mountedin the tube sheet 316, such that after a period of use, the filtercartridge 322 can be removed and replaced with a new filter cartridge322.

The dust collector 300 illustrates a ladder 324 for accessing theinterior volume 306 of the housing 302. The ladder 324 extends to aplatform 326. The person servicing the dust collector 300 can climb theladder 324, stand on the platform 326, and then open a service door 328,which provides access to the interior volume 306. In this case, itprovides access to the clean air volume 318.

As can be seen in FIG. 8 , each of the filter cartridges 322 areoriented on the clean air side 317 within the clean air volume 318 ofthe housing 302. In this embodiment, no portion of the filter cartridges322 protrude or extend into the dirty air side 315 within the dirty airvolume 314; that is, the entire part of the filter cartridge 322 iswithin the clean air volume 318. Other embodiments could have the filtercartridges 322 or portions of the filter cartridges 322 within the dirtyair volume 314. However, in the embodiment shown, the entire filtercartridge 322 is within the clean air volume 318, which is convenientwhen servicing the dust collector 300. Because of the location of thefilter cartridge 322 within the clean air volume 318, the personservicing the dust collector 300 is subject to not as much dust anddebris. Of course, it should be understood, and will be explained later,that one of the flow faces of the filter cartridge 322 is exposed to thedirty air volume 314. In this embodiment, the filter cartridges 322 arepreferably flush with the tube sheet 316 and do not penetrate into thedirty air side 315.

The housing 302 further includes a clean air outlet, not shown in FIG. 8, but shown at 330 in FIG. 9 .

The dust collector 300 further includes a blower arrangement, not shown,to direct air from the dirty air inlet 312 (FIG. 9 ) to the clean airoutlet 330 (FIG. 9 ). The blower arrangement is typically locatedremotely from the dust collector 300, but is connected by duct work tothe clean air outlet 330 in air flow communication.

The dust collector 300 further includes an arm arrangement 332. The armarrangement 332 is movably mounted in the clean air side 317. It isoriented to move over the at least one filter cartridge 322 and todirect a jet of air through the downstream side 334 of the filtercartridge 322. What this does is back flushes the media in the filtercartridge 322, in order to remove at least some dust and debris from theupstream side of the media in the filter cartridge, which allows for thefilter cartridge 322 to operate longer.

The arm arrangement 332 is operably connected in air flow communicationto a compressed air tank 336. In the embodiment of FIG. 8 , the tank 336is within the clean air volume 318. In the embodiment of FIG. 9 , thecompressed air tank 336 is mounted outside of the housing 302, on a roof338 of the housing 302. The compressed air tank 336 is connected to aremote compressor, for providing the jet of air that is sent through thearm arrangement 332. In the embodiment of FIG. 9 , the dust collector isshown at reference numeral 300′, and is the same as the dust collector300 of FIG. 8 , except that the compressor 336 is mounted on the roof338.

FIGS. 22 and 23 to be discussed further below, illustrate an exampleembodiment of arm arrangement 332. The arm arrangement 332 includes anarm housing 340 defining a volume of an air distribution header 342(FIG. 25 ) within the arm housing 340. Extending from the arm housing340 and in air flow communication with the air distribution header is aplurality of nozzles 344. The nozzles 344 direct the jet of air from thecompressor tank 336, through the air distribution header 342, throughthe nozzles 344, and to the downstream side 334 of the filter cartridges322.

The arm arrangement 332 is movably mounted, so that the nozzles moveover each of the filter cartridges 322.

In the embodiment depicted in FIG. 8 , the arm arrangement 332 rotatesin a circle about a central axis, which, in this embodiment, aligns witha central axis of the tube sheet 316.

In operation, dirty air is drawn through the inlet 312 by way of theblower. The dirty air moves into the dirty air volume 314 on the dirtyair side 315 of the tube sheet 316. The dirty air then passes throughthe filter cartridge 322, where dust and debris is removed from the air.The filtered air then flows into the clean air volume 318 on the cleanair side 317 of the tube sheet 316. The clean air then exits the housing302 through the outlet 330. The arm arrangement 332 directs a jet of airthrough the downstream flow face of at least one of the filtercartridges 322 in order to remove at least some of the dust and debrisfrom the upstream side of the filter cartridge 322. The dust and debrisfalls by gravity into the hopper 308.

In the embodiment depicted in FIG. 8 , the arm arrangement 332 isconstructed and arranged to periodically direct a pulse of air at apressure of about 3-15 psi. With periodic pulsing at this pressurerange, which is a relatively low pressure version, the cleaning systemis operating as a reverse pulse cleaning system. Periodically, thecompressed air tank 336 containing a valve assembly will operate to fireor emit a pulse of air at this relatively low pressure range of 3-15psi. The pressure pulse will be emitted through the nozzles 344 and atthe downstream side 334 of the filter cartridge 322. This pulse of airwill then flow through the filter media and help to push any dirt ofdebris built up on the upstream side of the filter cartridge 322.

In another embodiment, the arm arrangement 332 operates at higherpressures, such as greater than 15 psi. In those arrangements, the armarrangement 332 is operably connected to the compressed air tank 336 andis constructed and arranged to periodically direct a pulse of air at apressure of greater than 15 psi at the downstream side 334 of the filtercartridges 322.

The embodiment of FIG. 10 illustrates another embodiment of a dustcollector 350. The dust collector 350 includes the same structure asdescribed above with respect to the dust collector 300, and as such,will carry the same reference numerals for these same parts. In thisembodiment, however, the arm arrangement 332 is operably connected to ablower 352 and is constructed and arranged to constantly direct a streamof air at the downstream side 334 of at least one filter cartridge 322.Such a cleaning system is referred to as a reverse flow cleaning system354. In the reverse flow cleaning system 354, rather than directing apulse of air, as in the embodiment of FIGS. 8 and 9 , there is aconstant stream of air that is directed from the nozzles 344 to at leastone of the filter cartridges 322. The constant stream of air isgenerally very low pressure, such as a pressure of less than 3 psi.

In the embodiment of FIG. 11 , a dust collector is shown at 350′. Thisdust collector 350′ is the same as the dust collector 350 of FIG. 10 ,except that the blower 352 has been moved to be outside of the interiorvolume 306 and onto the roof 338 of the housing 302.

In FIG. 12 , a dust collector 350″ is illustrated. The dust collector350″ is similar to the dust collector 350 shown in FIG. 10 , and similarfunctioning parts carry the same reference numerals. In this embodiment,the dust collector 350″ includes a double rotating reverse flow cleaningsystem 370. The double rotating reverse flow cleaning system 370includes at least a pair of arm arrangements 332, with only one of thearm arrangements 332 being clearly visible in FIG. 12 . The doublerotating reverse flow cleaning system will allow for constantlydirecting a stream of air at a pressure of less than 3 psi at more thanone filter cartridge 322 at a time. In this system, there are morefilter cartridges 322 utilized than in the systems of FIGS. 8-11 , andas such, it is convenient to have the double rotation reverse flowcleaning system 370. The system 370 includes the pair of armarrangements 332, each rotating about an axis, in order to constantlydirect a stream of air at a pressure of less than 3 psi at thedownstream side 334 of at least one filter cartridge 322.

IV. Example Filter Cartridges, FIGS. 13-20

Published PCT application 2008/106375 is incorporated herein byreference. PCT 2008/106375 discloses trapezoidal shaped filtercartridges and methods for making them.

In FIGS. 13-18 , one embodiment of filter cartridge 322 that is usablein any of the dust collectors described herein is illustrated at 420. Inthe embodiment shown, the cartridge 420 includes a media pack 422 havinga first flow face 424 (FIG. 16 ) and an opposite second flow face 426(FIG. 13 ). The media pack 422 includes a stack of strips 428 of singlefacer filter media material. Each strip 428 includes a fluted mediasheet 430 secured to a facing media sheet 432 and oriented with flutesof each fluted sheet 430 extending in a direction between the first andsecond opposite flow faces 422, 426. The media pack 422, is generally asdescribed in connection with FIG. 7 above.

The first flow face 424 (FIG. 16 ) comprises a planar inlet flow face434 having a non-rectangular perimeter shape 436. The shape 436 is,preferably, non-circular. In the preferred embodiment shown, the shape436 is a trapezoidal perimeter shape 438.

In the embodiment shown, the second flow face 426 (FIG. 13 ) is anoutlet flow face 440. When the filter cartridge 420 is operablyinstalled in one of the dust collectors as described herein, the outletflow face 440 will correspond to the downstream side 334 of the filtercartridge 322. As can be seen in FIG. 13 , in the preferred embodiment,the outlet flow face 440 also has a non-rectangular perimeter shape 441.In this embodiment, the shape 441 is also a trapezoid shape 442.Preferably, the trapezoid shape 442 is the same as the trapezoid shape438.

Still in reference to FIG. 13 , the air filter cartridge 420 depictedincludes a gasket member or seal gasket 444 around the media pack 422.Example orientations for the gasket 444 are described further below. Ingeneral, the gasket 444 is for providing a seal against the tube sheet316 so that air to be filtered does not bypass the filter cartridge 420;but rather, is forced to pass through the media pack 422.

Also visible in FIG. 13 is a mounting bracket arrangement 446. Themounting bracket arrangement 446 is for allowing the mounting of thefilter cartridge 420 to the tube sheet 316. In the embodiment shown, themounting bracket arrangement 446 is secured to the media pack 422 anddefines at least one fastener socket 448 to allow mounting of the filtercartridge 420 to the tube sheet 316. This is described further below.

As mentioned above, each strip 428 of single facer filter media materialhas a facing media sheet 432. Preferably, this facing media sheet 432 isnon-fluted. Preferably, it is a flat piece of material.

In FIG. 13 , the media pack 422 illustrates only a portion of the mediaacross the flow face 426. It should be understood that the entire planarsurface within the perimeter shape 441 would be formed of the strips428.

By reviewing FIGS. 13 and 16 , it can be appreciated that in thisembodiment, the media pack 422 includes a first side 450 and an oppositesecond side 452. The first and second sides 450, 452 extend between thefirst and second opposite flow faces 424, 426. In this embodiment, eachof the first and second sides 450, 452 are at least partially securedand in this embodiment, fully secured to corresponding first and secondside panels 454, 456.

A perimeter definition of the inlet flow face 434 (FIG. 16 ) includesfirst and second, opposite, non-parallel edges 458, 460 of differentlength. Also, the perimeter definition includes third and fourth,parallel edges 462, 464 of different lengths. As can be seen, the firstedge 458 extends generally perpendicular to the third and fourth edges462, 464.

The media pack 422 has, as described above, a first pair of opposite'sside, which are first and second sides 450, 452. The media pack, 422, inthis embodiment, also includes a second pair of opposite sides includingthird and fourth sides, 466, 468. The third and fourth sides 466, 468extend between the first and second opposite flow faces 424, 426 andalso between the first and second sides 450, 452. The third and fourthsides 466, 468 engage the first flow face 424 along the third and fourthedges 462, 464. The first and second sides 450, 452, engage the firstflow face 424 along the first and second edges 458, 460. The first edge458 has a different length than the second edge 460.

As can be seen in FIGS. 13 and 16 , in this embodiment, the first side450 extends in a plane that is non-parallel to the second side 452. Thethird edge 462 is shorter than the fourth edge 464, in this embodiment.In this embodiment, the third side 466 extends in a plane generallyparallel to the fourth side 468.

Preferably, the third side 466 and fourth side 468 are at leastpartially secured to panels or respective first and second end caps 470,472. The end cap 472 is illustrated in a perspective view in FIG. 14 .

In the preferred embodiment, a ratio of the third edge 462 to the fourthedge 464 is about 0.5-0.6. In one example, a ratio of the third edge 462to the first edge 458 is about 0.3-0.4. In one example, a ratio of thefourth edge 464 to the first edge 458 is about 0.6-0.8. In one example,an angle between the fourth edge 464 and the second edge 460 is about70-75 degrees.

As mentioned above, the filter cartridge 420 includes a gasket 444. Inthe embodiment shown, the gasket member 444 is secured to an end of theside panels 454, 456 and the end caps 470, 472. As can be seen in FIG.16 , the gasket 444 projects from the end of these panels 454, 456 andend caps 470, 472 and projects beyond a plane of the first flow face424. The gasket 444, in this embodiment, corresponds to the outerperimeter, and as such, forms a trapezoidal shape. The mounting bracketarrangement 446 helps to compress and squeeze the gasket 444 against thetube sheet 316 to form a seal. This is described below.

The mounting bracket arrangement 446, in this embodiment, includes atleast a first flange arrangement 474 radially extending from the thirdside 466. In particular, the first flange arrangement 474 is secured tothe first end cap 470 (FIG. 17 ) and includes an L-shaped flange 476.The flange 476 includes a socket 448 for receiving a fastener, such as abolt. The L-shaped flange 476 includes a radially extending leg 478(FIG. 15 ) and an axially extending foot 480. The foot 480 is orientedin a direction toward the first flow face 424, and it is radially spacedfrom the media pack 422 by the leg 478. The leg 478 defines the socket448. The foot 480 prevents the gasket 444 from being over-compressed bythe fastener, through the socket 448 and into the tube sheet 316. Thatis, the foot 480 operates as a stop to prevent the over tightening ofthe fastener. As can be seen in FIG. 15 , the foot 480 does not extendpast the gasket 444.

The mounting bracket arrangement 446 further includes at least a secondflange arrangement 482.

The second flange arrangement 482 radially extends from the fourth side468. In the particular embodiment shown, the second flange arrangement482 extends radially from the second end cap 472, which is secured tothe fourth side 468. In the embodiment shown, the second flangearrangement 482 includes a pair of linearly spaced flanges 484, 486.Each of the flanges 484, 486 defines a second socket 448 and a thirdsocket 448 for receiving a fastener to allow connection of the filtercartridge 420 over the aperature 320 in the tube sheet 316. In thepreferred embodiment, the flanges 484, 486 are constructed as describedabove for flange 476, including having a leg 478 and foot 480.

As can be seen in FIG. 16 , overall, in this embodiment the mountingbracket arrangement 446 includes a plurality of flanges 476, 484, 486,with each of the flanges 476, 484, 486 being linearly spaced from eachother and at least one of the flanges 476 being spaced radially from atleast one other flange in the plurality. In this embodiment, the flange476 is both linearly and radially spaced from both of the flanges 484,486.

In use, the filter cartridge 420 is removably mounted into or incovering relationship to the aperture 320 in the tube sheet 316. Theseal gasket 444 is axially against the clean air side 317 of the tubesheet 316. The bracket arrangement 446 matches up withfastener-receiving holes in the tube sheet 316. Fasteners are placedthrough the sockets 448 and into the receiving holes in the tube sheet316. The fasteners are tightened, which pushes the flanges 476, 484, 486in a direction toward the tube sheet 316. This causes a compression ofthe gasket 444 against the tube sheet 316, to form a seal therebetween.The gasket 444 cannot be over-compressed because the foot 480 on each ofthe flanges 476, 484, 486 will operate as a stop to prevent furtheraxial motion of the filter cartridge 420 toward the tube sheet 316.

FIG. 19 illustrates an alternative embodiment of the filter cartridge420. In FIG. 19 , a cartridge 488 is shown, and includes a media pack422 of strips 428 of single facer filter media material. The differencebetween the embodiment of FIGS. 13-18 and FIG. 19 is the trapezoidalperimeter shape. FIG. 19 shows an isoceles trapezoid, in which the firstedge 490 and second edge 492 have the same length as each other,although, they are non-parallel. The third edge 494 and fourth edge 496are parallel to each other, although unequal in length. The anglebetween the first edge 490 and fourth edge 496 is the same as the anglebetween the second edge 492 and the fourth edge 496; while the anglebetween the third edge 494 and first edge 490 is the same as the anglebetween the third edge 494 and second edge 492.

Although the filter cartridge 488 depicted does not show panels, endcaps, a gasket, or a mounting bracket, it should be understood that, inpractice, it would include these or components similar to these as shownin FIGS. 15-18 .

FIG. 20 illustrates another embodiment of a filter cartridge 500. Inthis embodiment, the media pack 502 is not stacked z-media, but rather,coiled z-media, such as described in connection with FIG. 6 . The coiledmedia pack 502 includes a first flow face 504 and an opposite, secondflow face, not shown in FIG. 20 . In should be understood, however, thatthe flow face is similar to the flow faces shown in FIGS. 13-16 . In theembodiment of FIG. 20 , the media pack 502 has a first rounded end 506and an opposite, second rounded end 508. Between the first and secondrounded ends 506, 508 are first and second straight sides 510, 511therebetween. The first rounded end 506 has a greater radius than thesecond rounded end 508.

In the embodiment shown, the cartridge 500 includes a non-circular core514. The media pack 502 is wound or coiled around the core 514. In thisembodiment, the core 514 is shown to be wedge or sector-shaped. Such anelement 500 would permit it to operably mount within the dust collectorsdescribed herein that have a circular tube sheet 316, and help to reducethe amount of non-filtering material occupied by the tube sheet 316.

V. Dust Collector System, FIG. 21

Turning now to the embodiment of FIG. 21 , another dust collector isshown at 360. The dust collector 360 is similar to the dust collector300 of FIG. 8 , and common reference numerals will describe commonparts. However, in the embodiment of FIG. 21 , there is a differentshaped tube sheet 362. In this embodiment, the tube sheet 362 isrectangular, even though the housing 302 is cylindrical. The tube sheet362 includes a plurality of apertures 364 for holding filter cartridges.

In general, it is desirable to maximize the filter media in the tubesheet, which, theoretically, would be done by providing a filter thesame size and shape of the collector housing/tube sheet. This is oftennot practical because of manufacturing difficulties and other problems,so in practice, smaller filter cartridges that can most effectively fillthis space are typically utilized. When the housing is cylindrical, thiscan be problematic because the filter cartridge would have to changeshape as the filter cartridge is located closer to the center of thetube sheet. One solution to this problem is illustrated in FIG. 21 byhaving inserted the rectangular tube sheet 362 between the dirty airside 315 and the clean air side 317 in order to increase the filtermedia area on the tube sheet 362.

Having a rectangular tube sheet 362 allows for using a filter cartridgewith a rectangular perimeter. Rectangular filter cartridges populating arectangular tube sheet 362 provide efficient utilization of the space ofa tube sheet 362.

The rectangular filter cartridges utilized in the tube sheet 362 can befilter cartridges of the type described above in connection with FIGS.1-7 using z-media.

VI. Nozzle Arrangements, FIGS. 22-27

As mentioned above in connection with the description of FIGS. 8-12 ,the arm arrangement 332, in this embodiment, includes an arm housing 340and at least one nozzle 344. The embodiment shown includes a pluralityof nozzles 344. The nozzles 344 are in air flow communication with theair distribution header 342 (FIG. 25 ).

As can be appreciated from reading the description of the embodiment ofFIGS. 8-12 , and the description of other embodiments of dustcollectors, such as FIG. 21 and FIG. 29 , these embodiments include themovable arm arrangement 332. The movable arm arrangement 332 isconstructed and arranged to move across the filter cartridges 322 inorder to direct an air stream at the downstream side 334 of the filtercartridges 322. As the arm arrangement 332 is moving, nozzles 344 areusually spaced some distance from the downstream side 334 of the flowface. If hard, rigid nozzles 344 were to physically contact thedownstream side 334 of the filter cartridges 322, it may result indamaging the filter cartridges 322. On the other hand, the distancebetween the nozzle 344 and the downstream side 334 of the filtercartridges 322 reduce the effectiveness of the cleansing jet of air thatis being emitted from the nozzles 334.

A solution to this problem is illustrated in FIGS. 22-26 . In thisembodiment, at least one of the nozzles 344, and preferably each of thenozzles 344 includes a flexible sleeve 414. The flexible sleeve 414, inthe embodiment shown, is attached at a perimeter 416 of the exhaustnozzle 344 and extends down to contact or overlap the downstream side334 of the filter cartridge 322. The flexible sleeve 414 can directlycontact the filter cartridge 322, without damage. The flexible sleeve414 will also reduce the problem of changes in the spacing betweenfilter cartridges 322 and the nozzles 344 due to manufacturingtolerances in large dust collectors. In preferred embodiments, theentire nozzle 344 could be made entirely from a flexible material.

In convenient implementations, the distance between the downstream side334 of the filter cartridge 322 and an endpoint 418 of the sleeve 414will be less than 1.0 inch.

Preferred materials for the sleeve 414 include natural and syntheticrubber, urethane, foams, plastics, and other types of materials thatresult in a flexible, non rigid property.

VII. Air Knife and Translational Movement Systems, FIGS. 28-32

FIG. 28 schematically shows a section of z-filter media 375, generallyas described in connection with FIGS. 1-7 above. In the schematic ofFIG. 28 , the principles of using a very high velocity reverse flowcleaning method are shown. By the term “very high velocity” it is meantvelocities of air at or greater than 10,000 feet per minute. These typesof velocities can be utilized with an air knife, one embodiment which isillustrated in FIGS. 29-31 .

A schematic representation of the air knife is shown at 326. The airknife 326 includes a manifold 378, which is an air flow communicationwith a pressure blower, not shown. The manifold 378 delivers the airfrom the pressure blower, and the air flows from the manifold 378through a nozzle 380.

The manifold 378 will have a width, which can be a diameter shown at382. The nozzle 380 will have a width of 384. It has been found that foreffective, efficient cleaning of the z-media 375, the width 384 of thenozzle 380 should be in the range of 0.05-0.0025 times the width 382 ofthe manifold 378. Preferably, the width 384 is about 0.015 times thewidth 382 of the manifold 378. This provides for an effectivedistribution and velocity for cleaning the z-media 375.

FIG. 28 also shows dirty air flow 386 and clean air flow 388.

The embodiment of FIGS. 29-32 show a dust collector 390 that utilize theprinciples of the air knife of FIG. 28 . While in the embodiments ofFIGS. 8-12 , the arm arrangement 332 was movable by rotating about acentral, longitudinal axis, in the embodiment of FIGS. 29 and 30 , thearm arrangement 332 moves in a translational direction, such asbi-directionally in a single plane over the at least one filtercartridge 322.

In FIG. 29 , the housing 302, in this embodiment, is rectangular incross-section. It defines a clean air outlet 330 in the side of thehousing 302. The tube sheet 316 can be seen in FIG. 29 , and the cleanair side 317 of the tube sheet 316 resting in the clean air volume 318is also visible. The dust collector 390 includes an access door 392 toallow selective access to the clean air volume 318 in order to servicethe filter cartridges mounted over the aperture 320 in the tube sheet316. In FIG. 29 , it should be noted, the filter cartridges 322 are notshown, for purposes of clarity of understanding.

Also, illustrated in the embodiment of FIG. 29 is a housing 394 for alinear actuator motor. A connector 396 is shown for a high pressureblower.

In the interior volume 306, specifically the clean air volume 318 of thehousing 302, an embodiment of an air knife 398 is shown. The air knife398 includes a manifold 399 and a nozzle 401 (FIG. 32 ) for delivering ajet of air at a very high velocity.

The air knife 398 is secured to a pressure blower (not shown) at fitment404, as shown in phantom lines.

In this embodiment, the arm arrangement 332 includes at least one arm406 that moves laterally, or by-directionally across the tube sheet asshown at arrow 408. A linear actuator 410 moves the arm 406non-rotationally, in a line back and forth as shown at 408. The arm 406,in this embodiment, includes the air knife 398. In other embodiments,something other than an air knife could be used, such as the same typesof arm arrangements 332 utilized above in connection with FIGS. 8-12 .

The air knife 398 is constructed and arranged to deliver a jet of air avelocity of greater than 10,000 feet per minute at the downstream sideof the filter cartridges 322 mounted over or within the apertures 320 inthe tube sheet 316. Preferably, the air knife 398 is constructed andarranged to deliver a jet of air at a velocity of greater than 26,000feet per minute.

One particularly useful embodiment includes filter cartridges 322 havingz-media of the type described in connection with FIGS. 1-7 and utilizingan air knife where a width of the nozzle is 0.05-0.0025 times thediameter of the manifold. In one preferred implementation, a width ofthe nozzle is about 0.015 times the diameter of the manifold.

VIII. Example Principles

An air filter cartridge is provided an may include: a media pack havingfirst and second opposite flow faces; the media pack comprising a stackof strips of single facer filter media material, each strip including afluted media sheet secured to a facing media sheet and oriented withflutes of each fluted sheet extending in a direction between the firstand second, opposite, flow faces; the first flow face comprising aplanar inlet flow face with a non-rectangular perimeter shape; a sealgasket extending around the media pack; and a mounting bracketarrangement secured to the media pack defining at least one fastenersocket to allow mounting of the filter cartridge to a tube sheet.

Each strip of single facer may have a facing sheet that is non-fluted.

Each flow face may have a non-circular perimeter shape.

The first flow face may have a trapezoidal perimeter shape.

The media pack may include first and second, opposite, sides extendingbetween the first and second, opposite, flow faces; each one of thefirst and second sides being a least partially secured to acorresponding one of first and second side panels.

A perimeter definition of the inlet flow face may include: first andsecond, opposite, non-parallel edges of different length; and third andfourth, parallel, edges of different lengths.

The first edge may extend generally perpendicular to the third andfourth edges.

The media pack may have a first pair of opposite sides; and a secondpair of opposite sides; the first pair of opposite sides comprisingfirst and second sides extending between the first flow face and thesecond flow face and engaging the first flow face along first and secondedges; the first edge having a different length than the second edge;and the second pair of opposite sides comprising third and fourth sidesextending between the first and second opposite, flow faces and alsobetween the first and second sides; the second pair of opposite sidesengaging the first flow face along third and fourth edges.

The first side may extend in a plane non-parallel to the second side.

The third edge may be shorter than the fourth edge.

The third side may extend in a plane generally parallel to the fourthside.

A ratio of the third edge to the fourth edge can be 0.5-0.6.

A ratio of the third edge to the first edge can be 0.3-0.4.

A ratio of the fourth edge to the first edge can be 0.6-0.8.

An angle between the fourth edge and the second edge can be 70-75degrees.

The mounting bracket arrangement may include at least a first flangearrangement radially extending from the third side; the first flangearrangement defining a first fastener socket.

The mounting bracket arrangement may include at least a second flangearrangement radially extending from the fourth side; the second flangearrangement defining a second and third fastener socket.

The second flange arrangement may include a pair of linearly spacedflanges. The mounting bracket arrangement may include a plurality offlanges; each of the flanges being linearly spaced from each other; andat least one of the flanges being spaced radially at least one other inthe plurality.

The media pack may be surrounded by a pair of side panels and a pair ofend caps; and the gasket member may be secured to an end of the sidepanels and end caps and projects beyond a plane of the first flow face.

An air filter cartridge is provided and may include a coiled media packhaving a first flow face and an opposite second flow face; the mediapack including: a set of inlet flutes open at the first flow face topassage of air to be filtered therein; a set of outlet flutes open atthe second flow face; the media pack being closed to flow of unfilteredair into the first flow face and then outwardly from the second flowface without filtering;

the media pack having first and second rounded ends with first andsecond straight sides therebetween; and the first rounded end having agreater radius than the second rounded end.

The cartridge may include a non-circular core; the media pack may bewound around the core.

The core may be generally sector-shaped.

A dust collector is provided and may include: a housing having a dirtyair inlet and a clean air outlet; a blower arrangement to direct airfrom the dirty air inlet to the clean air outlet; a tube sheetseparating a dirty air side and a clean air side; the tube sheetdefining at least one aperture; at least one filter cartridge removablymounted to cover the aperture in the tube sheet; the filter cartridgeincluding a media pack having a first flow face and an opposite secondflow face; the media pack having: a set of inlet flutes open at thefirst flow face to passage of air to be filtered therein; a set ofoutlet flutes open at the second flow face; the media pack being closedto flow of unfiltered air into the first flow face and then outwardlyfrom the second flow face without filtering; the filter cartridge beingoriented to clean air as it flows from the dirty side, through the firstflow face of the media pack and then through the second flow face of themedia pack to the clean air side; and an arm arrangement movably mountedin the clean air side oriented to move over the at least one filtercartridge and direct a jet of air through the second flow face of the atleast one filter cartridge to the first flow face

The arm arrangement may be operably connected to a compressed air tank.

The arm arrangement may include at least one arm mounted to rotate abouta central axis over the at least one filter cartridge.

The arm arrangement may include at least a pair of arms mounted torotate about a central axis over the at least one filter cartridge.

The tube sheet may define a plurality of apertures; and the at leastfilter cartridge may include a plurality of filter cartridges, such asfilter cartridges characterized above.

The housing may be cylindrical; the tube sheet may be rectangular; andthe at least one filter cartridge may have a rectangular perimeter.

The arm arrangement may include a plurality of nozzles; and at least oneof the nozzles may include a flexible sleeve extending therefrom.

The arm arrangement may include at least one arm mounted to movebi-directionally in a single plane over the at least one filtercartridge.

The arm arrangement is operably connected to a compressed air tank andmay be constructed and arranged to periodically direct a pulse of air ata pressure of 3 psi-15 psi.

The arm arrangement is operably connected to a compressed air tank andmay be constructed and arranged to periodically direct a pulse of air ata pressure of greater than 15 psi.

The arm arrangement is operably connected to the blower and may beconstructed and arranged to constantly direct a stream of air at apressure of less than 3 psi.

The arm arrangement may include an air knife constructed and arranged todeliver a jet of air at a velocity of greater than 10,000 feet/minute.

The arm arrangement may include an air knife constructed and arranged todeliver a jet of air at a velocity of greater than 26,000 feet/minute.

The air knife may include a manifold and a nozzle; the manifold defininga diameter and the nozzle defining a width; a width of the nozzle may be0.05 to 0.0025 times the diameter of the manifold. A width of the nozzlemay be about 0.015 times the diameter of the manifold.

The above are principles. Many embodiments can be made applying theseprinciples.

What is claimed is:
 1. An air filter cartridge comprising: (a) a coiledmedia pack having a first flow face and a second flow face which isopposite of the first flow face; the coiled media pack including: (i) aset of inlet flutes open at the first flow face to passage of air to befiltered therein; (ii) a set of outlet flutes open at the second flowface; (iii) the coiled media pack being closed to flow of unfiltered airinto the first flow face and then outwardly from the second flow facewithout filtering; (b) the coiled media pack having first and secondrounded ends with at least a first straight side and a second side incomplete extension therebetween; (i) the coiled media pack having alength extending along a straight line from a center of the firstrounded end to a center of the second rounded end; (i) the coiled mediapack having a first width between the first straight side and secondside; the first width being perpendicular to the length; (ii) the coiledmedia pack having a second width thereacross; the second width beingperpendicular to the length; and (iii) wherein the first width isnarrower than the second width.
 2. An air filter cartridge according toclaim 1 further comprising: a non-circular core; the coiled media packbeing wound around the non-circular core.
 3. An air filter cartridgeaccording to claim 2 wherein: the non-circular core is generallysector-shaped.
 4. An air filter cartridge according to claim 1 wherein:the first flow face is planar.
 5. An air filter cartridge according toclaim 1 wherein: the coiled media pack includes fluted sheet secured toa facing sheet.
 6. An air filter cartridge according to claim 1 furthercomprising: a wedge-shaped core; the coiled media pack being woundaround the wedge-shaped core.
 7. An air filter cartridge according toclaim 1 wherein: the first flow face and second flow face are planar. 8.An air filter cartridge according to claim 1 wherein: the coiled mediapack has a third width thereacross extending between two sides of one ofthe first rounded end or the second rounded end; the third width beingperpendicular to the length; and wherein the third width is narrowerthan the first width.
 9. An air filter cartridge according to claim 1wherein: the second side is a straight side in complete extensionbetween the first and second rounded ends.